Fluid drive for oil well drilling draw works



April 28, 1964 A. F. 1.. ANDERSON 3,130,824

FLUID DRIVE FOR OIL WELL DRILLING DRAW WORKS Filed Nov. 7, 1960 INVENTOR. Axe; FLA/memo BY United States Patent 3,130,824 FLUID DRIVE FUR OIL WELL DRILLING DRAW WORKS Axel F. L. Anderson, Detroit, Mich, assignor to American Radiator dz Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Filed Nov. 7, 1969, Ser. No. 67,688 3 Claims. (til. 192-33) This invention relates to power transmitting drive means, as for example drive means adapted for use between the power plant and operated devices in oil well drilling apparatus.

In conventional rotary oil well drilling apparatus there is provided a draw works for controlling the pressure on the drill bit and for withdrawing the drill string during bit replacement periods and other periods. The drill bit is driven within the earth by means of a rotary table suitably keyed to the upper pipe in the string. Lubrication of the bit and carry-off of the cuttings is effected by pumping a slurry or mud down the string and thence upwardly therearound back to the earth surface.

The power plant for rotary well drilling installations thus must supply power for three principal requirements, namely operating the draw works, turning the rotary table, and driving the mud pumps.

During the normal drilling operations the power from the power plant is divided between the rotary table and mud pumps. During the operation of raising the drill string from the hole the rotary table and mud pumps are idle, and the power is directed only to the draw works. In deep well drilling it is not uncommon to spend as much time raising and lowering the string as is spent in active operation at the bottom of the hole. Therefore the trend has been toward larger power plants in order to speed up these hoisting operations. In the usual installation the power plant employs a multiple number of engines in order to achieve desired flexibility in drive, to thus attain best performance during each operation. The demand for increased power has resulted in the use of larger engines as well as the use of more engines in each power plant. In the usual installation the multiple engines making up the power plant are connected to operate as a common unit by means of a system of chains, sprockets and clutches, with necessary shafts and bearings. It is thus possible to apply the power of one, all or any desired number of engines to drive the mud pumps, rotary system, or draw works according to instantaneous requirements.

The mud pumps require the greatest amount of power so that the power plant must be operated at a speed which will meet the requirements of the mud pumps. However the speed of the rotary system requires adjustment so that the drill bit will rotate at the correct speed for the drilling conditions at any one time. In present day design of the rotary table this adjustment can be roughly adjusted by the selection of a gear ratio in the selected gear box contained in the rotary system. Exact adjustment to instantaneous drilling requirements is not usually possible since all of the engines in the power plant are required to drive the mud pumps (which determine the power plant speed).

It is therefore an object of the present invention to provide oil well drive apparatus having means for achieving an infinite speed adjustment of the rotary table without changing the speed of the power plant (which has been adjusted to the requirements of the mud pumps).

Another object of the invention is to provide oil well drive means wherein the power input to the rotary table is limited or what might be considered cushioned so that the torque will not reach the point of breaking the drill bit and/ or drill pipe.

3,133,824 Patented Apr. 28, 1964 An additional object of the invention is to provide an oil Well drive means wherein the power and speed imparted to the draw works is limited and controlled, whereby to make precise hoisting of the drill pipe possible when excessive pull or speed of hoisting would endanger the drill pipe and drilling tools.

A further object of the invention is to provide a general application drive unit which incorporates a fluid coupling and friction clutch in parallel with one another between the input and output so that the output may be locked up to the input with the friction clutch or driven at selected slower speeds by operation of the fluid coupling.

A further object of the invention is to provide a drive unit as above specified, wherein the drive elements are mounted together on a common output shaft, the arrangement being characterized by a simplicity of con-. struction and low first cost.

Another object is to provide a drive unit having a minimum number of bearings and low maintenance costs.

Another object is to provide a drive unit of T6121? tively compact construction such as to permit it to be quickly mounted in a small floor space as a unitary assembly.

An additional object of the invention is to provide a drive unit, including a single centrally disposed output shaft, an input drum of annular construction surrounding the output shaft, a fluid coupling located in the annular space between the drum and shaft for transmitting a variable speed drive from the drum to the shaft, and a friction clutch located in the annular space between drum and shaft for transmitting a locked-up drive from the drum to the shaft.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

' In the drawings the single figure is a sectional view of one embodiment of the invention.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying draw: ings, since the invention is capable of other embodiments and of being practiced or carried out in various Ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to the drawings, there is shown therein a drive unit 10 compising a casing structure 12 including a bottom wall 14, end walls 16 and 18, and a top wall 20. Two additional unnumbered walls are extended between walls 16 and 18 to complete the casing structure.

Positioned externally of casing 12 is a conventional antifriction bearing structure 22 for supporting a portion of a horizontal shaft 24, said shaft extending through the bearing structure and with in the casing 12, with the left end portion thereof being supported in a bearing assembly indicated generally by numeral 26. As shown in the drawings, bearing assembly 26 is carried within a machinedout recess in the internal boss 28 on casing end wall 18.

In the illustrated embodiment shaft 24 constitutes the output member of the drive unit. The input for the drive unit is provided by a series of sprockets 30 formed integrally with a hub member 32. It will be understood that in service each of the sprockets 30 has trained therearound a chain, and that the chains are driven from a suitable power device such as a gasoline engine, diesel engine, etc. (not shown). Suitable bearings 25 are provided for supporting hub 32 and the left end of drum 36 (to be 3 described later), it being understood that bearings 25 do not transmit a drive from the hub to the shaft.

As shown in the drawings hub 32 is formed as an integral extension of the end plate 34 which is carried and forms part of the drum structure indicated generally by numeral 36. The illustrated drum structure includes two cylindrical flanged members 38 and 40, and a third annular flanged member 42 having an inwardly angled annular extension 44. It will be understood that the various elements 38, 40 and 42 are rigidly secured together, as by means of bolts passed through their mating pheripheral flanges. The arrangement is such that rotation of hub 32 by the power chains is effective to rotate drum 36.

Disposed in the annular space between drum 36 and shaft 24 is a fluid coupling indicated generally by the numeral 46. The coupling includes a conventional impeller 48 which connects with drum element 40, and a conventional runner 50 rigidly connected with the output shaft 24, as by key-keyway means; the impeller and runner are of course suitably vaned to provide a work chamber 78.

The fluid coupling is supplied with working fluid from a sump 52 formed between the lower portions of walls 16 and 18. The fluid is pumped from the sump by means of a vane type pump 54 which may be constructed as shown in US. patent application, Serial No. 612,993 filed October 1, 1956, now Patent No. 2,961,967. As shown in the accompanying drawing the pump is provided with a drive shaft 56, and the aforementioned hub 32 is provided with a sprocket (not visible), around which is trained an endless chain 58. Chain 58 is also trained around a sprocket carried on pump shaft 56 so that rotation of hub 32 drives pump 54 at a desired speed such that fluid is pumped from the sump 52 into the discharge pipe 60 extending frrom an upper portion of the pump casing.

As shown in the illustrative drawings, pipe 60 connects with an external pipe 62 which leads to a cooler (not shown). After its passage through the cooler the fluid is returned to the illustrated unit through a pipe 64 which connects with an internally disposed tubing section 66 Tubing section 66 in turn is connected with a cylindrical conduit 68 which is provided with the conically flared discharge wall or baffle 70. It will be seen that operation of pump 54 is effective to pump fluid from sump 52, through pipes 60 and 62, into the cooler (not shown), thence through pipe 64, tubing section 66 thence into conduit 68, and finally into the chamber or space 72 formed between the back surface of runner 50 and the runner casing 74.

The inner surface of the runner casing guides the fluid into the annular clearance space 76 around the periphery of the runner so that the fluid can then move into the work chamber 78 via the spaces between the impeller and runner blades. In practice the arrangement is such that the fluid is centrifugally maintained in the outer portions of chamber 72 so that a desired amount of fluid is introduced into the work chamber 78, for causing any desired slip characteristic between the impeller and runner. The drawings show an arrangement wherein fluid passes through chamber 72 before entering work chamber 78; this is an economical arrangement. However it is contemplated that the fluid could be fed directly into the work chamber, as through a passage (not shown) in shaft 24.

It will be seen that in the illustrated embodiment casing 74 is provided with a number of peripheral openings 80 so that fluid which is discharged from the duct 68 is enabled to ultimately move into the space or chamber 82 defined within the inwardly directed wall 44. In practice the fluid levels within chambers 72 and 82 are centrifugally maintained substantially the same so that any subtraction of fluid out of the chamber 82 would be accompanied by a corresponding alteration of the fluid level in chamber 72, as through openings 80.

Subtraction or withdrawal of fluid out of chamber 82 may be accomplished by the means of a scoop tube 84. As shown in the illustrative drawings the scoop tube is of straight, non-arcuate construction and is guided for rectilinear motion by means of the guide brackets 86 and 88. As shown in the illustrative drawings, bracket 88 is fixedly mounted on duct 68, and bracket 86 is fixedly mounted therebelow, as by securing it on the mounting flange 69 of duct 68.

The scoop tube 84 angles outwardly of the plane of the paper from the lower end to the upper end thereof so as to clear the surface of duct 68. The lower end of the scoop tube is about on a line directly below output shaft 24, and is equipped with an aperture or port 90 for reception of fluid from the chamber 82.

Control of the scoop tube position may be effected by means of the assembly designated generally by numeral 91. As shown in the drawings assembly 91 comprises a horizontal rotary shaft 93 extending within the upper portion of casing 12 and externally thereof so as to be connectable with a control device (not shown) such as an air motor, electric motor, or manual adjustor. Shaft 93 carries a crank arm 95 from which is pivotally suspended a link 97 having a pivotal connection with a collar 99 suitably aflixed to the scoop tube. It will be seen that with the illustrated. arrangement clockwise movement of shaft 93 raises the scoop tube and counterclockwise movement of shaft 93 lowers the scoop tube.

In operation of the coupling, fluid which is centrifugally received through the port 90 is directed upwardly in the scoop tube and is subsequently discharged through the tube opening 92 into the sump 52. It will be seen that by moving the scoop tube 84 upwardly and downwardly in the guides 86 and 88 the level of fluid in chamber 82 can be regulated and controlled.

As previously noted the fluid level in chamber 82 also determines the fluid level in chamber 72, as well as the quantity of fluid within work chamber 78. The amount of working fluid within chamber 78 at any one time is effective to control the amount of slip between impeller 48 and the runner 50 so that the end effect of moving the scoop tube 84 is to control the power imparted to runner 50 and output shaft 24. The actual speed of retation of shaft 24 will of course be determined by the output load and the power supplied to input drum 36. The output speed may be varied 'as necessary by operation of tube 84.

The drive of the illustrated fluid coupling is very advantageous in that it provides a cushioned drive to the output shaft, with a shock-absorption action and with the ability to easily and controllably give any suitable rate of acceleration or deceleration. However there are certain losses in the operation of all fluid couplings such that in the usual construction the power transmission is a maximum of about ninety-seven percent. In order to provide for one hundred percent power transmission (i.e. a locked-up condition) there is utilized in the illustrated construction a second drive unit indicated generally by the numeral 100.

As shown in the drawings, the driving unit 100 comprises a clutch disc 102 suitably keyed to the output shaft 24. Disc 102 is provided with an outer rim 104 which is spaced from the inner surface of drum element 38. The defined annular space is occupied by two annular flexible endless tubes 106 and 108. The outer surface areas of these tubes are suitably bonded to the inner surface of drum element 38 so that the tubes rotate therewith. The inner surface areas of the tubes are provided with a suitable friction pad or shoe 103.

In the de-energized condition of clutch 100 the inner surface area of shoe 103 is spaced slightly from the outer surfaces of the disc rim 104 so as to permit relative movement between the disc and tubes 106 and 108. Energization of the clutch is effected by pumping pressure fluid into the tubes 106 and 108. Thus, as the internal pressure within the tubes 106 and 108 is increased the tubes tend to expand so as to bridge the annular space between drum element 38 and rim 104, for thereby causing shoe 103 to frictionally engage the outer surface of the rim and transmit a locked-up drive from drum 36 to the clutch disc 102. The disc is, as previously stated, keyed to the output shaft 24 so that a complete drive is imparted to the shaft.

In order to provide the desired fluid pressure within the tubes 106 and 108 there may be provided a suitable source of gaseous pressure (not shown) such as compressed air, said source being suitably connected to the duct 27 which extends through a fixed fitting 29 into communication with the longitudinal bore or duct 31 formed within shaft 24. As shown in the drawings duct 31 extends from left to right within shaft 24 to connection with a short radially exending duct 33. The discharge from duct 33 in turn connects to an annular passage 35 formed within hub 32. Suitable tubing 37 is extended from passage 35 along the outer face of end plate 34, thence axially as at 39 along the outer surface of drum element 38, and thence inwardly through wall element 38 to fluid communication with tubes 106 and 108. The drawing shows a single tubing structure 37 for feeding the flexible tubes 106 and 108. However any number of such tubing structures could radiate from annular passage 35 to provide the desired pressure within the flexible tubes.

It will be understood that control of clutch 100 may be effected merely by controlling the pressure in supply line 37, as by utilizing an electrically-operated valve for alternately exhausting the pressure from line 27 (and tubes 106 and S) and increasing the pressure therein accordingly as it is desired to deenergize or energize the clutch. The described details of clutch construction and energization are to a certain sense merely illustrative of the concept of utilizing a mechanical clutch in the illustrated drive system, and it is contemplated that other clutch arrangements could be employed in practice of the invention.

From the above discussion it will be seen that with the illustrated arrangement any desired speed can be instantaneously developed in shaft 24, ranging from zero speed to that attained with a locked-up drive. The installation has particular application in the oil well drilling field and is suitable for use as a drive between the drilling apparatus power plant and the drilling components such as the rotary table, draw works and mud pumps. In such installations the speed of the power plant may be set at the point of the maximum eificiency in accordance with requirements of the mud pump, and the speed of the output shaft 24 may be infinitely adjusted to drive the draw works and rotary at various different speeds without need for changing the power element speed or output characteristic. The adjustment is obtained by operation of the scoop tube 84 as previously described. Full speed can be readily obtained by energizing the friction clutch 100.

It will be noted that the entire arrangement is quite compact and requires a relatively small floor space for installation. With the exception of bearing 22 the entire assembly is a single unitary structure so that installation onto a skid or the like may be easily accomplished.

The illustrated unit utilizes but four bearings, namely bearings 22 and 26 for output shaft 24, and bearings 25 and 79 for the input member 36. The bearings in each set of bearings are spaced quite far apart by the design of the unit so as to provide satisfactory performance and long service life.

It will be understood that the preceding description is illustrative of the invention and that variations in constructional detail and arrangement can be resorted to Without departing from the spirit of the invention as set forth in the appended claims.

1. In a power transmitting drive,

an output shaft rotatably mounted on a support,

an annular input drum coaxial to and rotatably mounted in surrounding relation on said output shaft,

an Ennular space between said drum and said output s aft,

a fluid coupling in said space and having an impeller connected to said drum and a runner connected to said output shaft for transmitting power therebetween,

a positive lock-up clutch having a part connected to said input drum and a part connected to said output shaft to be operable between said drum and said output shaft,

said clutch being isolated from said fluid coupling by said impeller,

and means for actuating said positive lock-up clutch.

2. In a power transmitting drive,

an annular input drum,

means mounting said drum for rotation,

an output shaft extending coaxially within said drum,

a fluid coupling interposed between said drum and said output shaft, comprising an impeller secured to the interior of said drum,

a runner secured to said shaft,

and said impeller and runner being juxtaposed to define a toroidal work chamber for hydraulic liquid,

said drum including an annular extension partially enclosing said runner in spaced relation,

an annular casing connected to said drum and positioned between said annular extension and said runner and defining a first chamber spaced from said runner and a second chamber adjacent said runner,

said first chamber being in fluid communication with said second chamber,

said second chamber being in fluid communication with said work chamber,

means for supplying fluid to said second chamber,

a scoop tube movable in said first chamber to regulate the amount of fluid therein whereby the fluid levels in said first chamber, said second chamber and said work chamber are controlled,

and a positive lock-up clutch operatively connecting said output shaft and said input drum at a point spaced from said coupling.

3. In a power transmitting drive,

a housing having a sump therein for hydraulic fluid,

an output shaft having a portion extending into said housing,

means supporting said output shaft for rotation,

an input hub journaled in surrounding coaxial relation to said output shaft and outside of said housing,

an input drum Within said housing in surrounding coaxial relation to said output shaft,

means connecting said drum and said input housing for corotation,

a fluid coupling interposed between said drum and said output shaft, comprising an annular impeller secured to the inside of said input drum and surrounding said output shaft,

an annular runner secured to said output shaft in surrounding relation,

said impeller and rlmner being juxtaposed to define a toroidal work chamber for hydraulic liquid and separated by a space,

an annular extension on said drum partially enclosing said runner in spaced relation,

an annular casing connected to said drum and positioned between said extension and said runner and defining a first chamber isolated from said runner and a second chamber contacting the runner,

a port in said annular casing connecting said first chamber and said second chamber in fluid communication,

i I claimz' and said second chamber also being in fluid communication with said work chamber through said space between said impeller and runner,

a scoop tube extensible into said first chamber for regulating the amount of liquid in said first chamber, said second chamber and said work chamber, the exhaust of said scoop tube discharging within said housing to said sump,

a pump in said sump and having anintake below the normal fluid level thereof, and an outlet,

means connecting said pump and said input hub in driving relation,

conduit means connecting said outlet of said pump and said second chamber,

anda positive lock-up clutch operative ly interposed between said input drum and said output shaft and comprising an annular clutch disc mounted coaxially on said output shaft and having a cylindrical friction rim,

an annular flexible tube mounted to the interior of said drum opposite said disc rim,

a friction pad carried by said tube in adjacent spaced relation to said friction rim,

and means for introducing pressurized fluid into said tube to force said pad into locking engagement with said friction rim and thereby provide a positive drive between said input drum and said output shaft,

and said clutch being spaced from said coupling.

References Cited in the file of this patent UNITED STATES PATENTS 1,960,705 Kochlin g May 29, 1934 2,049,673 Starr Aug. 4, 1936 2,354,174 Schmitter July 18, 1944 2,736,407 Smipl Feb. 28, 1956 2,750,018 Dundore June 12, 1.956 2,841,959 Snow July 8, 1958 2,865,483 Lives'ey Dec. 23, 1958 2,965,202 Ohristecnson Dec. 20, 1960 FOREIGN PATENTS 329,430 Italy Sept. 9, 1935 961,058 Germany Mar. 14, 1957 1,232,080 France Apr. 19', 1960 

1. IN A POWER TRANSMITTING DRIVE, AN OUTPUT SHAFT ROTATABLY MOUNTED ON A SUPPORT, AN ANNULAR INPUT DRUM COAXIAL TO AND ROTATABLY MOUNTED IN SURROUNDING RELATION ON SAID OUTPUT SHAFT, AN ANNULAR SPACE BETWEEN SAID DRUM AND SAID OUTPUT SHAFT, A FLUID COUPLING IN SAID SPACE AND HAVING AN IMPELLER CONNECTED TO SAID DRUM AND A RUNNER CONNECTED TO SAID OUTPUT SHAFT FOR TRANSMITTING POWER THEREBETWEEN, A POSITIVE LOCK-UP CLUTCH HAVING A PART CONNECTED TO SAID INPUT DRUM AND A PART CONNECTED TO SAID OUTPUT SHAFT TO BE OPERABLE BETWEEN SAID DRUM AND SAID OUTPUT SHAFT, SAID CLUTCH BEING ISOLATED FROM SAID FLUID COUPLING BY SAID IMPELLER, AND MEANS FOR ACTUATING SAID POSITIVE LOCK-UP CLUTCH. 